Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756246AbbFSVLt (ORCPT ); Fri, 19 Jun 2015 17:11:49 -0400 Received: from mail.linuxfoundation.org ([140.211.169.12]:51733 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755987AbbFSUje (ORCPT ); Fri, 19 Jun 2015 16:39:34 -0400 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, David Woodhouse Subject: [PATCH 4.0 039/105] iommu/vt-d: Fix passthrough mode with translation-disabled devices Date: Fri, 19 Jun 2015 13:35:29 -0700 Message-Id: <20150619203559.360060256@linuxfoundation.org> X-Mailer: git-send-email 2.4.4 In-Reply-To: <20150619203558.187802739@linuxfoundation.org> References: <20150619203558.187802739@linuxfoundation.org> User-Agent: quilt/0.64 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2181 Lines: 69 4.0-stable review patch. If anyone has any objections, please let me know. ------------------ From: David Woodhouse commit 4ed6a540fab8ea4388c1703b73ecfed68a2009d1 upstream. When we use 'intel_iommu=igfx_off' to disable translation for the graphics, and when we discover that the BIOS has misconfigured the DMAR setup for I/OAT, we use a special DUMMY_DEVICE_DOMAIN_INFO value in dev->archdata.iommu to indicate that translation is disabled. With passthrough mode, we were attempting to dereference that as a normal pointer to a struct device_domain_info when setting up an identity mapping for the affected device. This fixes the problem by making device_to_iommu() explicitly check for the special value and indicate that no IOMMU was found to handle the devices in question. Signed-off-by: David Woodhouse Signed-off-by: Greg Kroah-Hartman --- drivers/iommu/intel-iommu.c | 13 ++++++++----- 1 file changed, 8 insertions(+), 5 deletions(-) --- a/drivers/iommu/intel-iommu.c +++ b/drivers/iommu/intel-iommu.c @@ -673,6 +673,11 @@ static void domain_update_iommu_cap(stru domain->iommu_superpage = domain_update_iommu_superpage(NULL); } +static int iommu_dummy(struct device *dev) +{ + return dev->archdata.iommu == DUMMY_DEVICE_DOMAIN_INFO; +} + static struct intel_iommu *device_to_iommu(struct device *dev, u8 *bus, u8 *devfn) { struct dmar_drhd_unit *drhd = NULL; @@ -682,6 +687,9 @@ static struct intel_iommu *device_to_iom u16 segment = 0; int i; + if (iommu_dummy(dev)) + return NULL; + if (dev_is_pci(dev)) { pdev = to_pci_dev(dev); segment = pci_domain_nr(pdev->bus); @@ -2974,11 +2982,6 @@ static inline struct dmar_domain *get_va return __get_valid_domain_for_dev(dev); } -static int iommu_dummy(struct device *dev) -{ - return dev->archdata.iommu == DUMMY_DEVICE_DOMAIN_INFO; -} - /* Check if the dev needs to go through non-identity map and unmap process.*/ static int iommu_no_mapping(struct device *dev) { -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in Please read the FAQ at http://www.tux.org/lkml/